This page describes the accessibility stack of Debian and provides configuration hints for users. For general package maintainer information on accessibility in Debian, please look at the accessibility maintainer page. For development details, please look at accessibility-devel.

In addition to the existing hardware speech support in the installer of Squeeze (Debian 6), software speech is supported in Wheezy (Debian 7) and later: when you get at the boot menu (a beep should be emitted to indicate that), simply press s and enter. It can also be triggered from the win32-loader by choosing the expert installer, the graphical mode installation, and by appending speakup.synth=soft to the kernel commandline. Note however that the windows boot menu is not accessible, one has to press down and enter while it is showing up at boot (for 30s by default).

When installation is done via braille or speech, the same braille and speech parameters will get enabled on the installed system. Orca will also be enabled for the user created at installation.

If speech synthesis does not come up, we need information to find out where the bug is.

First and foremost, we need the exact URL where you have downloaded the installer image, otherwise we won't ever manage to find a bug which could only exist on the image you have used (and which has to be fixed too!)

Inside the installer, press alt-f2 to switch to a shell console, press enter to start the shell, and type

amixer scontrols

amixer scontents

cat /proc/asound/cards

and post the output to debian-accessibility@lists.debian.org so we can know whether a sound card was detected and what the volume level names are. If only an error message shows up, or if you do not have resources to be able to read the shell console, please try to run a live CD, make sound work with it, and post the output of lsmod to debian-accessibility@lists.debian.org so we can know what sound driver is missing.

Images for squeeze with software speech can be downloaded from http://people.debian.org/~sthibault/espeakup/ but they don't seem to be working any more due to kernel update in the official archive. As a replacement, the Wheezy images can be used, and when given the archive mirror choice, type '<' to get back to main menu, change the priority to lowest, enter the mirror selection part again in the main menu, and then one can choose to install Squeeze instead of Wheezy, and change the priority to high again with the same method.

To record some boot option and thus avoid typing them blindly, one can remaster an image by using the script below:

LiveCD accessibility

The gnome liveCD has screen reader support. At the boot menu, one has to type enter (TODO: add beep). Then the desktop launches up (TODO: add beep), and one can press super-alt-s to start Orca.

Braille support

Braille device support is handled by brltty, which is started as a background daemon. Most displays work under brltty, connected via either a serial port, USB or bluetooth. Details on supported braille devices can be found on the brltty website (http://www.mielke.cc/brltty/). It also provides screen reading support for the Linux text console. Screen reading support for the gnome desktop is provided by Orca . It does not drive braille devices itself, it "connects" to brltty via BrlAPI to do so. If Orca does not manage to output braille, make sure that

/etc/brlapi.key exists and contains something (the actual content doesn't matter, as long as it is not empty).

you have read permission on /etc/brlapi.key

brltty is up and running.

Some braille devices have an integrated braille keyboard. Brltty supports simulating keypresses on the text console. For proper simulation on Xorg (handle non-qwerty layouts, in particular), the brltty-x11 package should be installed. It provides xbrlapi, which should be started at Xorg session startup, before starting orca.

The PC keyboard can also be used as a braille keyboard. In /etc/brltty.conf, uncomment key-table keypad, and restart brltty. One can then switch to braille by pressing insert+asterisk on the numpad, and switch back to normal by pressing insert+slash on the numpad. The default is to use the asdfjkl, keys as braille keys, but /etc/brltty/kbd-braille.kti can be modified to use other keys.

One can also type unicode braille patterns (not letters, pure braille, shown as such on the screen) thanks to the console-braille package, which includes keyboard layouts and the setbrlkeys program to load them easily.

Brltty also has very basic graphical screen reading support, which is limited to text fields, e.g. edit's main widget, or gnome-terminal's terminal. This is shipped in the brltty-x11 package, and can be started by running

brltty -b ba -x as

at Xorg session startup. -b ba tells it to connect via BrlAPI to the already-running brltty that drives the actuall braille device. -x as selects the At-Spi driver, which performs graphical screen reading.

Speech support

Debian provides a lot of software speech syntheses, a list can be found in the speechsynthesis blend task. Screen readers can often directly use some of the speech syntheses, or use generic interfaces, such as speech-dispatcher. speech-dispatcher runs as a daemon, which screen readers can connect to in order to emit speech. speech-dispatcher then has several modules to support various speech syntheses.

Speech syntheses, especially on the command line, are known to have issues with pulseaudio. It is recommended to disable/remove pulseaudio, like described #Disable_Pulseaudio.

text console

Software speech syntheses are supported on the text console. There are two screenreaders within Debian which can make use of them, speakup and brltty.

Hardware speech syntheses are also supported on the text console through the speakup drivers. This however requires to disable the 8250 serial port driver by setting this variable in /etc/default/grub:

GRUB_CMDLINE_LINUX="8250.nr_uarts=0"

one can then add for instance this in /etc/modules to get a speakup module loaded:

Speech-Dispatcher

Also, if you do not have pulseaudio installed, you need to made speech-dispatcher revert to alsa: in /etc/speech-dispatcher/speechd.conf, uncomment the line AudioOutputMethod and set it this way:

AudioOutputMethod "alsa"

Testing Speech-Dispatcher

You can test whether speech-dispatcher works by running

spd-say "some text"

Or if you want to test a specific module like espeak:

spd-say -o espeak "some text"

audio level

Starting from Stretch, the audio levels are reset to a default value at bootup. If you want to change that default value, set the audio levels to the desired value (e.g. with alsamixer from the alsa-utils package), and save the settings by running as root

alsactl store

Embossers

Embossers can easily be used in text mode through the CUPS generic text driver:

In the printers panel (accessed through the printer icon in the control panel, or directly by browsing http://localhost:631/ and clicking on Administration), add a printer, choose the connexion (usb, parallel port, etc.), you can freely choose a description to your liking, and for the driver selection, choose the "Generic" maker, and choose the "Generic text-only printer" choice.

To print, you can then just run

lp test.txt

If your embosser doesn't do it automatically, you may need to reformat your text to the width of the paper by using the fmt command, for instance for 40 columns:

fmt -40 < test.txt > test2.txt
lp test2.txt

Accessible boot

GRUB can be made to beep when it is ready to take keyboard presses: in /etc/default/grub , uncomment or add the following line:

GRUB_INIT_TUNE="480 440 1"

and run update-grub

An option to get a completely accessible bootloader is to use petitboot. The principle is to make the normal bootloader (e.g. Grub) boot Linux normally, but making it start petitboot and brltty. Petitboot provides the list of kernels to boot, and permits to append parameters, and then uses kexec to boot the desired kernel with the desired options.

Then, create a boot entry for petitboot. For instance, copy/paste from /boot/grub/grub.cfg a Linux entry (which is known to boot fine) to the end of /etc/grub.d/40_custom , append at the end of the linux line (that specifies the vmlinux file) init=/boot/petitboot.sh , and name the menu entry petitboot. You can also choose a hotkey for the entry. So for instance it should look like:

You may want to keep a backup of the known-to-boot kernel in a safe place, and use that path instead of the Debian-provided file whose upgrades might break.

Eventually, run update-grub to update /boot/grub/grub.cfg.

That way, at boot when you get the grub beep, you have the option to press the "End" key then "Enter", or press the hotkey "p", and that will boot linux, brltty, and petitboot.

If after good testing you really feel safe enough, you can make it the default in grub: in /etc/default/grub, set

GRUB_DEFAULT="petitboot"

and re-run update-grub . You still have the option, when grub beeps, to press "Begin" then "Enter" to boot without petitboot.

Console fonts

The Linux text console font can be tuned to get better accessibility: in /etc/default/console-setup, one can set FONTFACE to Terminus, in order to be able to select bigger fonts such as even FONTSIZE=32x16. That will of course reduce the amount of text displayed on the screen too. To fine-tune the exact amount of text displayed on the screen, SCREEN_WIDTH and SCREEN_HEIGHT can be set.

The console-braille package provides braille fonts, which you can use to type unicode braille patterns, and show braille on the physical screen. This is incompatible with using FONTFACE, as you will need to specify both the normal font and the braille font in the FONT variable, see example in /etc/default/console-setup .

Each desktop has a way to enable accessibility. You can also do it by hand, see among the tips&tricks below.

For KDE accessibility, the qt-at-spi package needs to be installed, and the QT_ACCESSIBILITY environment variable has to be set to 1:

export QT_ACCESSIBILITY=1

Color Themes for accessibility

The GNOME magnifier supports inverting colors. However, some people prefer other colors for the graphical environment or prefer to have only high contrast without all colors inverted. For this there is a package called gnome-accessibility-themes, where different themes are included. You can install it with

Option 3: Desktop Environment

The previous solutions work for any Debian system. However, depending upon which desktop environment you have installed, you may also have a simple graphical way to enable zooming. For example, Gnome-Shell and Cinnamon both include a Universal Access icon universalaccess.svg on their dock with a menu option to enable full screen zoom & pan.

Option 4: Compiz

Enhanced magnification support was provided by Compiz, but it is no longer packaged in Debian. It was reported by Shaun Marolf in 2015 that Ubuntu's Compiz packages work in Debian without modification, but that has not been tested.

Deprecated: Changing DPI

An older method which may no longer work (and probably should be deleted from this wiki) was to tell the Xserver that it had a higher resolution display than it really had:

To change DPI: xrandr --dpi 200

which will make everything basically two times bigger (200 dpi instead of the standard 96dpi or even 75dpi). Some elements may not get resized, one can put the following in ~/.gtkrc-2.0:

Magnifying Glass

Some people prefer using a virtual magnifying glass instead of magnifying the entire screen. The screen resolution is not changed, instead a small window is added which shows a magnified version of a portion of the screen. Usually you can choose where to be magnify by dragging inside the window or by having the program always magnify the region around the mouse. There are again different possibilities, you are free to choose from the following:

Option 1: Kmag

Kmag is simple to use. It will take up more disk space (>200MiB) if you don't already have KDE installed. Although designed for KDE, Kmag works with any desktop environment, including Gnome and Cinnamon.

Option 2: Virtual Magnifying Glass

If you have trouble reading only occasional words, you may prefer Virtual Magnifying Glass (VMG). Its advantage is that it is usually not visible, unlike programs such as kmag which create a window that always covers part of your screen. Clicking on the VMG icon in the tray shows a zoomed lens around your mouse pointer. Moving the mouse, moves the lens. Clicking anywhere closes the program. (Tip: To change the zoom level, roll the mouse-wheel.)

GNOME Magnifier

GNOME magnifier used to be the recommended magnifying glass tool for Debian. However, we will not cover it here as it is no longer packaged (as of Debian Jessie and Stretch).

gdm accessibility

The gdm graphical greeter supports accessibility, orca just needs to be enabled. But in Lenny the default installed gdm doesn't support this feature. So for Lenny you need, firstly, to remove gdm, and install gdm3 instead. Squeeze and later already use gdm3 by default.

Then, you can enable orca with either of four ways:

It is enabled automatically when accessibility features were enabled to access the Debian Installer

It can be enabled by clicking on the "accessibility" icon which brings a configuration panel.

Starting from Jessie, it can be enabled by typing the menu-alt-s shortcut.

lightdm accessibility

The lightdm graphical greeter supports accessibility, orca just needs to be enabled. Create the file /etc/xdg/lightdm/lightdm.conf.d/80_orca-dm-wrapper.conf and write the following in it:

[SeatDefaults]
greeter-wrapper=/usr/bin/orca-dm-wrapper

Iceweasel/firefox accessibility

The version of iceweasel/firefox in Wheezy is not as accessible as later versions. It is recommended to download, install, and use a newer version of firefox on mozilla.com

The version in Jessie is much more accessible.

32bit applications accessibility

If you are running a 64bit system, and use some 32bit applications, having libatk-adaptor installed will not be enough for making 32bit applications accessible: you need to also install the 32bit version of the package. If you have not done it already, enable i386 package installation, as documented in great details on Multiarch/HOWTO:

dpkg --add-architecture i386

Then update the APT database:

apt-get update

and you can now install the 32bit version of the bridge:

apt-get install libatk-adaptor:i386

Java accessibility

To access Java applications, one needs to install the libatk-wrapper-javapackage. Unfortunately, in some versions, openjdk has disabled accessibility by default (See 705511), so one has to reenable it by hand. In the file /etc/java-6-openjdk/accessibility.properties for Debian 7 (Wheezy) or /etc/java-7-openjdk/accessibility.properties for Debian 8 (Jessie) the following line must be uncommented (the # in front needs to be removed):

assistive_technologies=org.GNOME.Accessibility.AtkWrapper

Also, only the GTK look and feel has accessibility support, so in the file /etc/java-6-openjdk/swing.properties for Debian 7 (Wheezy) or /etc/java-7-openjdk/swing.properties for Debian 8 (Jessie) the following line must be uncommented (the # in front needs to be removed):

swing.defaultlaf=com.sun.java.swing.plaf.gtk.GTKLookAndFeel

Virtualization

Virtualizations tools are more or less accessible

Xen

Xen uses a command-line interface, so is of course accessible. Setting up a Xen environment is however not so easy. See the Debian Xen wiki pages.

qemu/kvm

qemu/kvm can be run in text-mode, by using the -curses option. Of course, when the guest is in graphical mode, the text interface will not show anything useful, and a screen reader will still be needed inside the guest.

To let that screen reader emit speech, the -soundhw ac97 option can be used to provide the guest with a virtual sound board.

To let the screen reader emit braille, the -usbdevice brailleoption can be used to provide the guest with a virtual Baum braille device. The braille rendering will be done through the host brltty daemon.

Another way for braille is to pass-through a USB braille device. For instance, if on the host lsusb reports the braille device as:

Bus 001 Device 002: ID 0403:fe72 Baum

Giving the -usbdevice host:0403:fe72 option will give the USB device to the guest, i.e. you must first make sure that nothing like brltty in the host uses it, then run qemu/kvm, and then a brltty daemon inside the guest can access the physical device, as if it was connected to the virtual machine.

Of course, if one has two USB braille devices, one can be used by a brltty running on the host, and the other by a brltty running in the guest.

Troubleshooting

No Speech After Login In GNOME

If Orca only says "Welcome to Orca" and seems to be silent then, you are actually on an empty desktop. To get the focus, press Alt+F1 for the menu or Alt+F2 for the run-dialog.

BRLTTY/braille stops after boot

In Wheezy there has been added a program called modemmanager which scans serial (and possibly usb2serial) devices to detect it as a modem. Unfortunately this destroys the communication with braille displays connected via those ports. Just

apt-get remove modemmanager

to repair this issue.

Inaccessible GNOME 3 session / no fallback mode

It can happen that you end up in a inadequately accessible GNOME 3 session. For instance, if you press alt+f1 for the menu, nothing is spoken. This has to do with the not-yet well accessible GNOME shell. Please see below how to resolve this problem.

Debian Wheezy (GNOME 3.4)

In GNOME 3.4, there is a mode called fallback mode, which mimes the behavior of GNOME 2. You can enable it using:

gsettings set org.gnome.desktop.session session-name gnome-fallback

It must be done from the GNOME session. One can get a terminal by pressing Alt+F2, entering gnome-terminal<enter> and this will be accessible anyway.

Debian Jessie (GNOME >= 3.8)

In Debian Jessie with GNOME version >= 3.8, there is a mode called GNOME classic. This one uses the GNOME shell directly to achieve GNOME 2 alike user experience. When using startx, you can set up your .xinitrc as follows to use this mode:

speech-dispatcher issues

Some users use the ibmtts or viavoice speech-synthetiser with orca, and they think that it is not convenient. According to them, the speech synthetiser is slow, its reactivity is slow, and it often crashes. The problem is that no alternative seems to exist, as gnome-speech is no longer supported by ibmtts' vendors.

However, the package who connects ibmtts to gnome-speech is under the LGPL. So, it was packaged and its name in Debian is gnome-speech-ibmtts.

NOTE: if you install ibmtts after the Debian package, you have to do: dpkg-reconfigure gnome-speech-ibmtts otherwise, the viavoice config file will not be generated and orca will not see viavoice at the starting of the preferences menu.

NOTE: you likely will need to do, before the first reboot of orca, a backup of your ~/.local/share/orca, then delete the contents of its contents. Do this with:

This process allows users who do not want to use speech-dispatcher immediately to find a solution. Anyway, this solution is not ideal for the long-time future, as gnome-speech, or at-spi, will be deprecated with Gnome-3. It can however be a good transition. But it does not work for amd64 architectures. Only i386 is supported.

Note that you do not experience this issue if you migrate from lenny (5.0) to squeeze (6.0), as the migration maintains the necessary configuration so that ibmtts can be accessed via gnome-speech.

In the meanwhile, one can use the dummy driver, which will not make use of any graphical card, and still let the gnome desktop start etc. Install the xserver-xorg-video-dummy package, and add the following lines to /etc/X11/xorg.conf (create one if you don't have any):

XFCE

The accessibility support for XFCE has to be enabled manually. This can be achieved either by clicking the "Enable assistive technologies" checkbox in the XFCE accessibility settings, or by running this command in an X session:

The file might already exist. If you haven't configured XFCE yet, you can replace the content of this file by the above excerpt. Please note that this will drop your XFCE session configuration. If you don't want to lose your existing XFCE session parameters, just add another "general" property, it will look like this:

For now, orca will not autostart. The simple workaround is to just drop the "?OnlyShowIn" line in /etc/xdg/autostart/orca-autostart.desktop , or to add XFCE to it.

LXDE and LXQT

For now, orca does not start automatically. The simple workaround is to just drop the "?OnlyShowIn" line in /etc/xdg/autostart/orca-autostart.desktop. Alternatively, LXDE or LXQT can be added at the end of this line.

Accessibility in chroots

In order for applications to be accessible from within chroots, they need to have access to the at-spi bus. This bus lives in both /tmp and $HOME, so the following is needed, in addition to the usual at-spi configuration inside the chroot:

to reactivate it. It is also a good idea (but not required) to add a setting to your sudoers file to allow this command to be executed without password prompt. Add in /etc/sudoers:

user ALL=(root) NOPASSWD: /usr/sbin/vbetool

.(where "user" must be replaced with the user name.)

Tip: After some time of inactivity, the monitor will be activated again after a key press. To avoid this you could create a script, called with ./<script_name> & to run it in the background and with the following content:

while [ 1 ]; do; sudo vbetool dpms off; sleep 20; done

The second approach differs for the console and X. On the text console, that can be done through

setterm -blank force

and restored through

setterm -blank poke

That needs to be run directly on the Linux console. When running through screen, you need to redirect the output e.g. to /dev/tty1:

setterm -blank force > /dev/tty1

On the graphical X11 console, that can be done using this script to toggle the display off and on:

faster speaking eSpeak

The eSpeak speech synthesis can speak faster by adding a configuration option to the appropriate voices file. Those voices files can be found under /usr/lib/i386-linux-gnu/espeak-data/voices/. Pick there your language file (e. g. en-us or de). Open the appropriate file as administrator in a text editor and insert the following line: